package us.clubadvocate.client.index;

import java.util.List;

import com.google.gwt.core.client.JavaScriptObject;

class FileSaver
{
  static
  {
    defineBlobs();
    defineFileSaver();
  }

  // ----------------------------------------------------------------------------
  
  public static native boolean checkSaveAs()
  /*-{
    if(typeof saveAs === "undefined")
      return false;
    return true;
  }-*/;
  // ----------------------------------------------------------------------------
  
  public static void saveStringToFile(List<String> strings, String filename)
  {
    StringArray sArr = getEmptyStrArray();
    for(String s : strings)
    { sArr.push(s); }
    Blob b = makeBlob(sArr);
    saveAs(b, filename);
  }
  
  // ----------------------------------------------------------------------------
  
  public static StringArray makeStringArray(String [] strings)
  {
    StringArray sArr = getEmptyStrArray();
    for(String s : strings)
    { sArr.push(s); }
    return sArr;
  }
  
  // ----------------------------------------------------------------------------
  
  public static native Blob makeBlob(StringArray arr)
  /*-{
    var bb = new Blob(arr, {type: "text/plain;charset=" + $doc.characterSet});
    return bb;
  }-*/;
  
  // ----------------------------------------------------------------------------
  
  public static native void saveAs(Blob blob, String filename)
  /*-{
    $wnd.saveAs(blob, filename);
  }-*/; // saveAs

  // ---------------------------------------------------------------------------
  // ---------------------------------------------------------------------------
  
  public static class StringArray extends JavaScriptObject
  {
    protected StringArray(){}
    
    public native final void push(String str)
    /*-{
      this.push(str);
    }-*/;
  }
  
  // ---------------------------------------------------------------------------
  // ---------------------------------------------------------------------------
  
  public static class Blob extends JavaScriptObject 
  {
    protected Blob(){}
  }
  
  // ----------------------------------------------------------------------------
  
  private static native StringArray getEmptyStrArray()
  /*-{
    return [];
  }-*/;
  
// -----------------------------------------------------------------------------
// -----------------------------------------------------------------------------

private static native void defineBlobs()
/*-{
  if (typeof Blob !== "function" || typeof URL === "undefined")
    if (typeof Blob === "function" && typeof webkitURL !== "undefined") 
    { $wnd.URL = webkitURL; }
    else 
    { 
      var Blob = (function (view) 
      {
          "use strict";
          var BlobBuilder = view.BlobBuilder || view.WebKitBlobBuilder || view.MozBlobBuilder || view.MSBlobBuilder || 
            (function(view) 
            {
                var get_class = function(object) { return Object.prototype.toString.call(object).match(/^\[object\s(.*)\]$/)[1]; };
                var FakeBlobBuilder = function BlobBuilder() { this.data = []; };
                var FakeBlob = function Blob(data, type, encoding) 
                {
                  this.data = data;
                  this.size = data.length;
                  this.type = type;
                  this.encoding = encoding;
                };
                
                var FBB_proto = FakeBlobBuilder.prototype;
                var FB_proto = FakeBlob.prototype;
                var FileReaderSync = view.FileReaderSync;
                var FileException = function(type) { this.code = this[this.name = type]; }
                var file_ex_codes = ("NOT_FOUND_ERR SECURITY_ERR ABORT_ERR NOT_READABLE_ERR ENCODING_ERR " + "NO_MODIFICATION_ALLOWED_ERR INVALID_STATE_ERR SYNTAX_ERR").split(" ");
                var file_ex_code = file_ex_codes.length;
                var real_URL = view.URL || view.webkitURL || view;
                
                var real_create_object_URL = real_URL.createObjectURL;
                var real_revoke_object_URL = real_URL.revokeObjectURL;
                var URL = real_URL;
                var btoa = view.btoa;
                var atob = view.atob;
                var ArrayBuffer = view.ArrayBuffer;
                var Uint8Array = view.Uint8Array;
                
                FakeBlob.fake = FB_proto.fake = true;            
                while (file_ex_code--) 
                { FileException.prototype[file_ex_codes[file_ex_code]] = file_ex_code + 1; }
                
                if (!real_URL.createObjectURL) 
                { URL = view.URL = {}; }
                
                URL.createObjectURL = function(blob) 
                {
                  var type = blob.type, data_URI_header;
                  if (type === null) 
                  { type = "application/octet-stream"; }
                  
                  if (blob instanceof FakeBlob) 
                  {
                    data_URI_header = "data:" + type;
                    if (blob.encoding === "base64")
                    { return data_URI_header + ";base64," + blob.data; } 
                    else if (blob.encoding === "URI") 
                    { return data_URI_header + "," + decodeURIComponent(blob.data); } 
                    if (btoa)
                    { return data_URI_header + ";base64," + btoa(blob.data); } 
                    else 
                    { return data_URI_header + "," + encodeURIComponent(blob.data);}
                  } 
                  else if (real_create_object_URL) 
                  { return real_create_object_URL.call(real_URL, blob); }
                };
                
                URL.revokeObjectURL = function(object_URL) 
                {
                  if (object_URL.substring(0, 5) !== "data:" && real_revoke_object_URL) 
                  { real_revoke_object_URL.call(real_URL, object_URL); }
                };
                
                FBB_proto.append = function(data) 
                {
                  var bb = this.data;
                  if (Uint8Array && (data instanceof ArrayBuffer || data instanceof Uint8Array)) 
                  {
                    var str = "", buf = new Uint8Array(data), i = 0, buf_len = buf.length;
                    for (; i < buf_len; i++) 
                    { str += String.fromCharCode(buf[i]); }
                    bb.push(str);
                  } 
                  else if (get_class(data) === "Blob" || get_class(data) === "File") 
                  {
                    if (FileReaderSync) 
                    { var fr = new FileReaderSync; bb.push(fr.readAsBinaryString(data)); } 
                    else
                    { throw new FileException("NOT_READABLE_ERR"); }
                  } 
                  else if (data instanceof FakeBlob) 
                  {
                    if (data.encoding === "base64" && atob)
                    { bb.push(atob(data.data)); } 
                    else if (data.encoding === "URI") 
                    { bb.push(decodeURIComponent(data.data)); } 
                    else if (data.encoding === "raw") 
                    { bb.push(data.data); }
                  } 
                  else 
                  {
                    if (typeof data !== "string") 
                    { data += ""; }
                    bb.push(unescape(encodeURIComponent(data)));
                  }
                };
                
                FBB_proto.getBlob = function(type) 
                {
                  if (!arguments.length) 
                  { type = null; }
                  return new FakeBlob(this.data.join(""), type, "raw");
                };
                
                FBB_proto.toString = function() { return "[object BlobBuilder]"; };
                
                FB_proto.slice = function(start, end, type) 
                {
                  var args = arguments.length;
                  if (args < 3) { type = null; }
                  return new FakeBlob(this.data.slice(start, args > 1 ? end : this.data.length), type, this.encoding);
                };
                
                FB_proto.toString = function() { return "[object Blob]"; };
                return FakeBlobBuilder;
          }(view));
        
          return function Blob(blobParts, options) 
          {
            var type = options ? (options.type || "") : "";
            var builder = new BlobBuilder();
            if (blobParts) 
            {
              for (var i = 0, len = blobParts.length; i < len; i++) 
              { builder.append(blobParts[i]); }
            }
            return builder.getBlob(type);
          };
    }($wnd));
    
    $wnd.Blob = Blob;
  }
}-*/; // End defineBlobs

// -----------------------------------------------------------------------------
// -----------------------------------------------------------------------------

private static native void defineFileSaver()
/*-{
  if(typeof saveAs !== "undefined")
    return;
  else
  {
    var tempSaveFunc;
        
    if(typeof navigator.msSaveBlob !== "undefined")
    {
     tempSaveFunc = (navigator.msSaveBlob && navigator.msSaveBlob.bind(navigator)) 
    }
    else
    {  
    tempSaveFunc = (function(view) {
    "use strict";
    var
        doc = view.document
        // only get URL when necessary in case BlobBuilder.js hasn't overridden it yet
      , get_URL = function() {
        return view.URL || view.webkitURL || view;
      }
      , URL = view.URL || view.webkitURL || view
      , save_link = doc.createElementNS("http://www.w3.org/1999/xhtml", "a")
      , can_use_save_link = "download" in save_link
      , click = function(node) {
        var event = doc.createEvent("MouseEvents");
        event.initMouseEvent(
          "click", true, false, view, 0, 0, 0, 0, 0
          , false, false, false, false, 0, null
        );
        node.dispatchEvent(event);
      }
      , webkit_req_fs = view.webkitRequestFileSystem
      , req_fs = view.requestFileSystem || webkit_req_fs || view.mozRequestFileSystem
      , throw_outside = function (ex) {
        (view.setImmediate || view.setTimeout)(function() {
          throw ex;
        }, 0);
      }
      , force_saveable_type = "application/octet-stream"
      , fs_min_size = 0
      , deletion_queue = []
      , process_deletion_queue = function() {
        var i = deletion_queue.length;
        while (i--) {
          var file = deletion_queue[i];
          if (typeof file === "string") { // file is an object URL
            URL.revokeObjectURL(file);
          } else { // file is a File
            file.remove();
          }
        }
        deletion_queue.length = 0; // clear queue
      }
      , dispatch = function(filesaver, event_types, event) {
        event_types = [].concat(event_types);
        var i = event_types.length;
        while (i--) {
          var listener = filesaver["on" + event_types[i]];
          if (typeof listener === "function") {
            try {
              listener.call(filesaver, event || filesaver);
            } catch (ex) {
              throw_outside(ex);
            }
          }
        }
      }
      , FileSaver = function(blob, name) {
        // First try a.download, then web filesystem, then object URLs
        var
            filesaver = this
          , type = blob.type
          , blob_changed = false
          , object_url
          , target_view
          , get_object_url = function() {
            var object_url = get_URL().createObjectURL(blob);
            deletion_queue.push(object_url);
            return object_url;
          }
          , dispatch_all = function() {
            dispatch(filesaver, "writestart progress write writeend".split(" "));
          }
          // on any filesys errors revert to saving with object URLs
          , fs_error = function() {
            // don't create more object URLs than needed
            if (blob_changed || !object_url) {
              object_url = get_object_url(blob);
            }
            if (target_view) {
              target_view.location.href = object_url;
            }
            filesaver.readyState = filesaver.DONE;
            dispatch_all();
          }
          , abortable = function(func) {
            return function() {
              if (filesaver.readyState !== filesaver.DONE) {
                return func.apply(this, arguments);
              }
            };
          }
          , create_if_not_found = {create: true, exclusive: false}
          , slice
        ;
        filesaver.readyState = filesaver.INIT;
        if (!name) {
          name = "download";
        }
        if (can_use_save_link) {
          object_url = get_object_url(blob);
          save_link.href = object_url;
          save_link.download = name;
          click(save_link);
          filesaver.readyState = filesaver.DONE;
          dispatch_all();
          return;
        }
        // Object and web filesystem URLs have a problem saving in Google Chrome when
        // viewed in a tab, so I force save with application/octet-stream
        // http://code.google.com/p/chromium/issues/detail?id=91158
        if (view.chrome && type && type !== force_saveable_type) {
          slice = blob.slice || blob.webkitSlice;
          blob = slice.call(blob, 0, blob.size, force_saveable_type);
          blob_changed = true;
        }
        // Since I can't be sure that the guessed media type will trigger a download
        // in WebKit, I append .download to the filename.
        // https://bugs.webkit.org/show_bug.cgi?id=65440
        if (webkit_req_fs && name !== "download") {
          name += ".download";
        }
        if (type === force_saveable_type || webkit_req_fs) {
          target_view = view;
        } else {
          target_view = view.open();
        }
        if (!req_fs) {
          fs_error();
          return;
        }
        fs_min_size += blob.size;
        req_fs(view.TEMPORARY, fs_min_size, abortable(function(fs) {
          fs.root.getDirectory("saved", create_if_not_found, abortable(function(dir) {
            var save = function() {
              dir.getFile(name, create_if_not_found, abortable(function(file) {
                file.createWriter(abortable(function(writer) {
                  writer.onwriteend = function(event) {
                    target_view.location.href = file.toURL();
                    deletion_queue.push(file);
                    filesaver.readyState = filesaver.DONE;
                    dispatch(filesaver, "writeend", event);
                  };
                  writer.onerror = function() {
                    var error = writer.error;
                    if (error.code !== error.ABORT_ERR) {
                      fs_error();
                    }
                  };
                  "writestart progress write abort".split(" ").forEach(function(event) {
                    writer["on" + event] = filesaver["on" + event];
                  });
                  writer.write(blob);
                  filesaver.abort = function() {
                    writer.abort();
                    filesaver.readyState = filesaver.DONE;
                  };
                  filesaver.readyState = filesaver.WRITING;
                }), fs_error);
              }), fs_error);
            };
            dir.getFile(name, {create: false}, abortable(function(file) {
              // delete file if it already exists
              file.remove();
              save();
            }), abortable(function(ex) {
              if (ex.code === ex.NOT_FOUND_ERR) {
                save();
              } else {
                fs_error();
              }
            }));
          }), fs_error);
        }), fs_error);
      }
      , FS_proto = FileSaver.prototype
      , saveFunc = function(blob, name) {
        return new FileSaver(blob, name);
      }
    ;
    FS_proto.abort = function() {
      var filesaver = this;
      filesaver.readyState = filesaver.DONE;
      dispatch(filesaver, "abort");
    };
    FS_proto.readyState = FS_proto.INIT = 0;
    FS_proto.WRITING = 1;
    FS_proto.DONE = 2;
    
    FS_proto.error =
    FS_proto.onwritestart =
    FS_proto.onprogress =
    FS_proto.onwrite =
    FS_proto.onabort =
    FS_proto.onerror =
    FS_proto.onwriteend =
      null;
    
    view.addEventListener("unload", process_deletion_queue, false);
    return saveFunc;
  }($wnd));
    }
    
    $wnd.saveAs = tempSaveFunc;
  }
}-*/; // End defineFileSaver


}
